The invention defines a method for evaluating half carcasses, also known as sides, of slaughtered animals that are detected at the product entrance, classification points, or product exit in slaughterhouses and meat packing facilities, by optical image processing. As a rule, inside the slaughterhouses and meat packing facilities, these half carcasses are transported, hanging from a hook, by means of special transport systems. The evaluation presented here is designed in particular for sides of pork, but it is also suitable in principle for sides of cattle, sheep, goats, or other large and small slaughtered animals.
In general, the sides of pork are registered, weighed and evaluated. The sides of pork are evaluated commercially by an appropriate official market classification. The thickness of the fat and of the flesh is detected at legally prescribed points specific to particular countries or states. For sorting purposes, a market value determination of the carcasses is made, as a rule; the finding is more conclusive if many further specific parameters are included, but usually these are not standardized.
German Patents DE 41 09 345 C2 and DE 44 08 604 C2 disclose an analysis or evaluation of carcass halves by means of image processing. In this processing, a photogrammetrical assessment of partial images of the carcass halves is done, beginning at the rumpbone. A disadvantage of such methods is that the rumpbone, as a prominent point in the picture of the carcass halves, is not adequately reliably selectable under the usual conditions in slaughterhouses, since because of mistakes in splitting the carcass that sometimes occur (if the division is not precisely in the plane of symmetry of the carcass), portions of the spinal column are missing from one half of the carcass or are covered with leaf fat, also known as pork flare, yet the spine is known to be located in only a narrow region of the plane of symmetry of the body of the animal. Another disadvantage is that selecting the spinal column is complicated and requires much computation by way of object analysis with predefined contour and object parameters.
The object of the invention is to develop a method that assures evaluation of carcass halves by image processing while overcoming the above disadvantages; in particular with a method that is simple to achieve in terms of computation, adequately reliable evaluation is intended to be accomplished, even if splitting errors mean that the plane of symmetry is missed when the carcasses are split.
This object is attained with the characteristics recited in claim 1. Further features of the invention will become apparent from the dependent claims.
The object is attained essentially in that for the photogrammetrical evaluation and assessment, only those body components that extend anatomically over a wide region relative to the plane of symmetry of the carcass and are reliably detectable visually are used; the hipbone, the gluteus medius muscle (MGM), in particular, and the back fat meet these requirements.
Because there are two hipbones, which meet solely in the plane of symmetry (inside the hip joint), the cut always runs through a hipbone and is thus optically visible and can be reliably evaluated by computation. Because it cannot be overlapped by leaf fat, the split surface cannot be visually concealed. The MGM and the back fat extend in the same over broad portions of the width of the back and are always reliably selectable visually and by computation by way of the transitions in brightness or color.